A Transport Protocol to Exploit Multipath Diversity in Wireless Networks

Abstract

Abstract-Wireless networks (including wireless mesh networks) provide opportunities for using multiple paths. Multihoming of hosts, possibly using different technologies and providers, also makes it attractive for end-to-end transport connections to exploit multiple paths. In this paper, we propose a multi-path transport protocol, based on a carefully crafted set of enhancements to TCP, that effectively utilizes the available bandwidth and diversity provided by heterogeneous, lossy wireless paths. Our Multi-Path LOss-Tolerant (MPLOT) transport protocol can be used to obtain significant goodput gains in wireless networks, subject to bursty, correlated losses with average loss-rates as high as 50%. MPLOT is built around the principle of separability of reliability and congestion control functions in an end-to-end transport protocol. Congestion control is performed separately on individual paths and the reliability mechanism works over the aggregate set of paths available for an end-to-end session.MPLOT distinguishes between congestion and link losses through Explicit Congestion Notification (ECN), and uses Forward Error Correction (FEC) coding to recover from data losses. MPLOT uses a dynamic packet mapping based on the current path characteristics to choose a path for a packet. Use of erasure codes and block level recovery ensures that in MPLOT, the receiving transport entity can recover all data as long as a necessary number of packets in the block are received, irrespective of which packets are lost. We present a theoretical analysis of the different design choices of MPLOT, and show that MPLOT chooses its policies and parameters such that a desirable tradeoff between goodput with data recovery delay is attained. We evaluate MPLOT, through simulations, under a variety of test scenarios and demonstrate that it effectively exploits path diversity in addition to efficiently aggregating path bandwidths, while remaining fair to a conventional TCP flow on each path.

Game-Theoretic Scalable Offloading for Video Streaming Services over LTE and WiFi Networks

“…Path diversity has some advantages [44]: it can eliminate problematic vertical handover delay and increase the transmission rate and reliability, because the physical paths are independent of each other. In recent years, some efficient multipath transport protocols [18], [45], [46] and end-to-end virtual path construction systems [44], [47] have been proposed to overcome the limitations of single path transmission by harmonizing the multiple physical paths simultaneously. In addition, an access network discovery and selection function (ANDSF), which is an optional network element in the 3GPP evolved packet core (EPC), has been specified in 3GPP standards [48], [49] for efficient interworking between 3GPP and non-3GPP access networks.…”

Analysis of the scope of cooperative bandwidth sharing among mobile routers in vehicular networks

“…Similar researches on aggregating bandwidth of multiple interfaces or mobiles' cooperation to improve efficiency have been investigated in prior work [9][10][11][12][13][14][15][16][17][18][19][20][21].…”

“…Sharma et al [18] proposed a multi-path transport protocol, based on a carefully crafted set of enhancements to TCP, that effectively utilizes the available bandwidth and diversity provided by heterogeneous, lossy wireless paths.…”

Joint source-channel coding and optimization for mobile video streaming in heterogeneous wireless networks

“…Besides, encoded multi-path streaming (EMS) [29] and multi-path loss tolerant (MPLOT) [30] are typical protocols exploiting path diversity in wired/wireless multi-path networks based on erasure code. EMS scheme splits traffic loads over multiple paths according to the path loss rate and dynamically adjusts FEC redundancy.…”

“…Indeed, the inclusion of a wireless access network with high loss rate, long propagation delay, or low bandwidth can theoretically increase D total because more FEC redundancy may be required to compensate for the increased uncertainty. In order to find the optimal solution, we first rank all the available wireless networks according to their 'loss-free' bandwidth (μ r (1 − π r )), which has proven to be a good indicator of the network path quality [30]. Then, the optimal flow rate allocation vector can be obtained with a simple but effective search algorithm, i.e.,…”